1. Field of the Invention
This invention relates to a radiation detector and, in particular, to a radiation detector used in a radiation detector assembly for detecting a radiation such as γ-ray, X-ray etc.
2. Description of the Related Art
A conventional radiation detector is constructed such that a laminated body composed of multiple common electrode plates, multiple semiconductor cells and multiple electrode plates, where the laminated body is arranged as the common electrode plate, the semiconductor cell, the electrode plate, the common electrode plate, . . . , is disposed between two frames, and one frame is pin-fixed to the other frame (see, e.g., U.S. Pat. No. 6,236,051).
The radiation detector in U.S. Pat. No. 6,236,051 can reduce the region not capable of detecting radiation to enhance the detection efficiency of radiation since a pair of the semiconductor cells neighboring in the lateral direction share the common electrode plate.
However, the radiation detector in U.S. Pat. No. 6,236,051 has the problem that the distance between the semiconductor cells is difficult to strictly control to have a predetermined distance upon arranging in high density the multiple semiconductor cells since the radiation detector is constructed by the multiple components such as the common electrode plates and the semiconductor cells and dimension errors caused by the respective components are accumulated when the components are laminated. In addition, since the radiation detector in U.S. Pat. No. 6,236,051 is constructed by fastening two frames with pins, it is difficult to evenly apply the fastening pressure to the semiconductor cells so that the semiconductor cells and a single electrode plate may not be properly connected and, if fastened too strong, a mechanical stress may be applied to the semiconductor cells.